I. Acute corrosive gastritis: There is a history of ingestion of strong acids (sulfuric acid, hydrochloric acid, nitric acid), strong alkalis (sodium hydroxide, potassium hydroxide) or lysol. After ingestion, it causes digestive tract burns, resulting in severe pain in the mouth, throat, behind the sternum, and upper abdomen, accompanied by swallowing pain, dysphagia, frequent nausea, and vomiting.